Notification of delivery of a rrlp multilateration timing advance request message to a base station subsystem (bss)

ABSTRACT

The present disclosure describes various techniques for enabling a Serving GPRS Support Node (SGSN) to provide a Base Station System (BSS) with an indication that a Logical Link Control (LLC) Protocol Data Unit (PDU) sent to a given wireless device contains a Radio Resource Location services Protocol (RRLP) Multilateration Timing Advance Request message such that the BSS after transmitting the LLC PDU to the given wireless device may invoke Timing Advance estimation algorithms for reception of uplink Packet Associated Control Channel (PACCH) acknowledgement block(s) (e.g., Extended Coverage (EC)-PACCH acknowledgment block(s)) from the given wireless device.

CLAIM OF PRIORITY

This application is a continuation application of U.S. patentapplication Ser. No. 15/886,727, filed Feb. 1, 2018, now pending, whichclaims the benefit of priority to U.S. Provisional Application Ser. Nos.62/453,843 and 62/456,991, respectively filed on Feb. 2, 2017 and Feb.9, 2017; the entire contents of each of these documents are herebyincorporated herein by reference for all purposes.

RELATED PATENT APPLICATION

This application is related to the co-assigned U.S. patent applicationSer. No. 15/886,616 entitled “Notification of Ongoing MultilaterationTiming Advance (MTA) Procedure to a Serving GPRS Support Node (SGSN)”,which claims the benefit of priority to U.S. Provisional ApplicationSer. No. 62/453,843, filed on Feb. 2, 2017. The entire contents of eachof these documents are hereby incorporated herein by reference for allpurposes.

TECHNICAL FIELD

The present disclosure relates generally to the wirelesstelecommunications field and, more particularly, to various techniquesfor enabling a Serving GPRS Support Node (SGSN) to provide a BaseStation System (BSS) with an indication that a Logical Link Control(LLC) Protocol Data Unit (PDU) sent to a given wireless device containsa Radio Resource Location services Protocol (RRLP) MultilaterationTiming Advance Request message such that the BSS may invoke TimingAdvance estimation algorithms for reception of uplink Packet AssociatedControl Channel (PACCH) acknowledgement block(s) (e.g., ExtendedCoverage (EC)-PACCH acknowledgment block(s)) from the given wirelessdevice.

BACKGROUND

The following abbreviations and terms are herewith defined, at leastsome of which are referred to within the following description of thepresent disclosure.

3GPP 3rd-Generation Partnership Project

ASIC Application Specific Integrated Circuit BSS Base Station SubsystemBTS Base Transceiver Station CN Core Network DL Downlink DSP DigitalSignal Processor EC Extended Coverage EC-GSM Extended Coverage GlobalSystem for Mobile Communications eNB Evolved Node B

EDGE Enhanced Data rates for GSM Evolution

EGPRS Enhanced General Packet Radio Service GSM Global System for MobileCommunications GERAN GSM/EDGE Radio Access Network GPRS General PacketRadio Service IE Information Element IoT Internet of Things LLC LogicalLink Control LTE Long-Term Evolution MME Mobility Management Entity MPMMultilateration Positioning Method MS Mobile Station MTA MultilaterationTiming Advance MTC Machine Type Communications NB-IoT Narrow BandInternet of Things PACCH Packet Associated Control Channel PDN PacketData Network PDU Protocol Data Unit RAN Radio Access Network RLC RadioLink Control RRLP Radio Resource Location Services Protocol SGSN ServingGPRS Support Node SMLC Serving Mobile Location Center TA Timing AdvanceTBF Temporary Block Flow TS Technical Specification TSG TechnicalSpecification Group UE User Equipment UL Uplink WCDMA Wideband CodeDivision Multiple Access WiMAX Worldwide Interoperability for MicrowaveAccess

Extended Coverage: The general principle of extended coverage is that ofusing blind transmissions for the control channels and for the datachannels to realize a target block error rate performance (BLER) for thechannel of interest. In addition, for the data channels the use of blindtransmissions assuming MCS-1 (i.e., the lowest modulation and codingscheme (MCS) supported in EGPRS today) is combined with HARQretransmissions to realize the needed level of data transmissionperformance. Support for extended coverage is realized by definingdifferent coverage classes. A different number of blind transmissionsare associated with each of the coverage classes wherein extendedcoverage is associated with coverage classes for which multiple blindtransmissions are needed (i.e., a single blind transmission isconsidered as the reference coverage). The number of total blindtransmissions for a given coverage class can differ between differentlogical channels.

Timing Advance Information: Identifies the timing advance value a BSSdetermines to be applicable to the mobile station in the cell where ithas performed the MTA procedure and is part of the MTA relatedmeasurement information passed from the BSS to the SMLC during the MTAprocedure. When the RLC Data Block method or Extended Access Burstmethod is used for performing the MTA procedure (see 43.059 Draft ChangeRequest (CR) (Rel-14) v13.2.0, “Introduction of Multilateration,”Source: Ericsson LM, RAN WG6 telco #1 on ePOS_GERAN, dated Dec. 15,2016—the contents of which are hereby incorporated herein by referencefor all purposes), the timing advance value estimated by the BSS may beadjusted according to the “MS Transmission Offset” value extracted fromthe RLC Data Block or the Extended Access Burst (see “Analysis of MSTransmission Accuracy”, Source: Ericsson LM, RAN WG6 telco #1 onePOS_GERAN, dated Dec. 15, 2016—the contents of which are herebyincorporated herein by reference for all purposes) prior to the timingadvance value being forwarded by the BSS to the SMLC. Alternatively, the“MS Transmission Offset” value may be sent to the SMLC along with thecorresponding non-adjusted timing advance value wherein the SMLC is thenresponsible for performing the adjustment.

At the 3rd-Generation Partnership Project (3GPP) Technical SpecificationGroup (TSG) Radio Access Network (RAN) Meeting #72, a Work Item on“Positioning Enhancements for GERAN” was approved (see RP-161260; Busan,Korea; 13-16 Jun. 2016—the contents of which are hereby incorporatedherein by reference for all purposes), wherein one candidate method forrealizing improved accuracy when determining the position of a mobilestation (MS) is multilateration timing advance (MTA) (see RP-161034;Busan, Korea; 13-16 Jun. 2016—the contents of which are herebyincorporated herein by reference for all purposes), which relies onestablishing the MS position based on Timing Advance (TA) values inmultiple cells.

At the 3GPP TSG-RAN1 Meeting #86, a proposal based on a similar approachwas made also to support positioning of Narrow Band Internet of Things(NB-IoT) mobiles (see R1-167426; entitled “On timing advance basedmulti-leg positioning for NB-IoT;” Source: Ericsson LM; Gothenburg,Sweden; 22-26 Aug. 2016—the contents of which are hereby incorporatedherein by reference for all purposes). In regards to IoT devices, itexpected that in a near future, the population of Cellular IoT deviceswill be very large. Various predictions exist; one such prediction isthat there will be >60000 cellular IoT devices per square kilometer (seedraft CR 43.059 entitled “Introduction of Multilateration”, SourceEricsson LM, RAN WG6 telco #1 on ePOS_GERAN, dated: Dec. 15, 2016—thecontents of which are hereby incorporated herein by reference for allpurposes), and another prediction is that there will be 1000000 cellularIoT devices per square kilometer (see R1-167426; entitled “On timingadvance based multi-leg positioning for NB-IoT;” Source: Ericsson LM;Gothenburg, Sweden; 22-26 Aug. 2016—the contents of which are herebyincorporated herein by reference for all purposes). A large fraction ofthese cellular IoT devices are expected to be stationary, e.g., gas andelectricity meters, vending machines, etc. . . . . Extended CoverageGSM-IoT (EC-GSM-IoT) and NB-IoT are two standards for Cellular IoT thathave been specified by 3GPP TSG GERAN and TSG Radio Access Network(RAN).

Timing Advance (TA) is a measure of the propagation delay between a basetransceiver station (BTS) and the MS, and since the speed by which radiowaves travel is known, the distance between the BTS and the MS can bederived. Further, if the TA applicable to the MS is measured withinmultiple BTSs and the positions (i.e., longitude and latitude) of theseBTSs are known, the position of the MS can be derived using the measuredTA values. The measurement of the TA requires that the MS synchronize toeach neighbor BTS and transmit a signal time-aligned with the timing ofthe BTS estimated by the MS. The BTS measures the time differencebetween its own time reference, and the timing of the received signal(transmitted by the MS). This time difference is equal to two times thepropagation delay between the BTS and the MS (one propagation delay ofthe BTS's synchronization signal sent to the MS, plus one equalpropagation delay of the signal transmitted by the MS back to the BTS).

As shown in FIG. 1 (PRIOR ART), once a set of TA values TA₁, TA₂, andTA₃ are established using a set of one or more BTSs 102 ₁, 102 ₂, 102 ₃(only three shown) during a given positioning procedure, the position ofthe MS 104 can be derived through a so called Multilateration TimingAdvance (MTA) procedure wherein the position of the MS 104 is determinedby the intersection of a set of hyperbolic curves 106 ₁, 106 ₂, 106 ₃associated with each BTS 102 ₁, 102 ₂, 102 ₃. The calculation of theposition of the MS 104 is typically carried out by a serving positioningnode 110 (e.g., serving Serving Mobile Location Center 110 (SMLC 110)),which implies that all of the derived TA values TA₁, TA₂, and TA₃ andthe associated position information of the BTSs 102 ₁, 102 ₂, 102 ₃needs to be sent to the serving positioning node 110 (i.e., the servingSMLC 110) which initiated the positioning procedure. In this example,the BTSs 102 ₁, 102 ₂, 102 ₃ transmit their respective TA₁, TA₂, and TA₃to one BSS 108 which then transmits TA₁, TA₂, and TA₃ to the SMLC 110.The BSS 108 and SMLC 110 are both connected to a SGSN 112. It should beappreciated that each BTS 102 ₁, 102 ₂, 102 ₃ could also be connected todifferent BSSs (not shown) where in any configuration the SMLC 110 isstill provided with the calculated TA₁, TA₂, and TA₃.

At the 3GPP TSG-RANG Meeting #3, some enhancements to the procedure havebeen proposed wherein the Base Station System (BSS) 108 estimates withsufficient accuracy the Timing Advance value in the serving cell duringthe initiation of the Multilateration Timing Advance procedure.Referring to FIGS. 2A-2B (PRIOR ART), there is a signal diagram whichillustrates one of the proposed enhancements for allowing the BSS 108 toestimate the Timing Advance value in the serving cell during theinitiation of the Multilateration Timing Advance procedure. Thisproposed enhancement consists of introducing a new (EC-) Packet ChannelRequest message 202 in step 3 with an indication that the MS 104 isresponding to a paging request for positioning 204 from step 1. Thisallows the BSS 108 to use more advanced Timing Advance estimationalgorithms such as oversampling and interpolation during the receptionof the subsequent Radio Link Control (RLC) data block 206 (last step instep 3) containing the Logical Link Control (LLC) Protocol Data Unit(PDU) 208 and mobile station accuracy information 210. At the 3GPPTSG-RANG Meeting #3 it has also been proposed (but no solutionspresented) that in step 11 the BSS 108 should also be able to estimatethe Timing Advance value 212 in the serving cell on reception of the(Extended Coverage-) Packet Associated Control Channel ((EC-)PACCH)Packet Downlink Ack 214. Then, the BSS 108 could send at step 12 theestimated timing advance 212 (note: the estimated timing advance 212 isadjusted according to a “MS Transmission Offset” that the BSS 108receives from the MS 104 in the (EC-)PACCH Packet Downlink Ack 214, seethe definition of “Timing Advance Information” above) along with BTSreceiver accuracy and MS accuracy parameters (shown as MS accuracyinformation 216) to the SMLC 110 to update the serving cell relatedtiming estimation, thereby allowing the MS 104 to leave the serving cellto perform the Multilateration Timing Advance procedure in additionalcells without first performing the Multilateration Timing Advanceprocedure in the serving cell (note: the BTS receiver accuracy is passedto the SMLC 110 as part of the MS accuracy information 216 and isinformation that the BSS 108 is able to self-generate (i.e., the BTSreceiver accuracy portion of the MS accuracy information 216 is notpassed from the wireless device 104 to the BSS 108)). The presentdisclosure describes why the BSS 108 cannot perform steps 11-12 and thendiscloses a solution such that when implemented the BSS 108 can performsteps 11-12.

SUMMARY

A SGSN, a BSS, a wireless device, and various methods for addressing theaforementioned problems are described in the independent claims.Advantageous embodiments of the SGSN, the BSS, wireless device, and thevarious methods are further described in the dependent claims.

In one aspect, the present disclosure provides a SGSN configured tointeract with a BSS. The SGSN comprises a processor and a memory thatstores processor-executable instructions, wherein the processorinterfaces with the memory to execute the processor-executableinstructions, whereby the SGSN is operable to perform a receiveoperation, and a transmit operation. In the receive operation, the SGSNreceives, from the BSS, a BSSGP POSITION-COMMAND PDU which includes (i)a RRLP PDU, wherein the RRLP PDU includes a RRLP MTA Request messageintended for a target wireless device, and (ii) an indicator that thetarget wireless device is to perform a MTA procedure. In the transmitoperation, the SGSN transmits, to the BSS, a BSSGP DL-UNITDATA PDU whichincludes a LLC PDU intended for the target wireless device, wherein theLLC PDU includes the RRLP PDU, wherein the RRLP PDU further includes theRRLP MTA Request Message, wherein the BSSGP DL-UNITDATA PDU furtherincludes a flag which indicates to the BSS a need to estimate timingadvance information when receiving a PACCH acknowledgment from thetarget wireless device. An exemplary advantage of the SGSN implementingthese operations is that the BSS is informed that it is to estimatetiming advance information when receiving a PACCH acknowledgment fromthe wireless device after the BSS transmits the LLC PDU to the wirelessdevice.

In another aspect, the present disclosure provides a method in a SGSNconfigured to interact with a BSS. The method comprises a receivingstep, and a transmitting step. In the receiving step, the SGSN receives,from the BSS, a BSSGP POSITION-COMMAND PDU which includes a RRLP PDU,wherein the RRLP PDU includes (i) a RRLP MTA Request message intendedfor a target wireless device, and (ii) an indicator that the targetwireless device is to perform a MTA procedure. In the transmitting step,the SGSN transmits, to the BSS, a BSSGP DL-UNITDATA PDU which includes aLLC PDU intended for the target wireless device, wherein the LLC PDUincludes the RRLP PDU, wherein the RRLP PDU further includes the RRLPMTA Request Message, wherein the BSSGP DL-UNITDATA PDU further includesa flag which indicates to the BSS a need to estimate timing advanceinformation when receiving a PACCH acknowledgment from the targetwireless device. An exemplary advantage of the SGSN implementing thesesteps is that the BSS is informed that it is to estimate timing advanceinformation when receiving a PACCH acknowledgment from the wirelessdevice after the BSS transmits the LLC PDU to the wireless device.

In yet another aspect, the present disclosure provides a BSS configuredto interact with a SGSN and a target wireless device. The BSS furthercomprises a processor and a memory that stores processor-executableinstructions, wherein the processor interfaces with the memory toexecute the processor-executable instructions, whereby the BSS isoperable to perform a first transmit operation, a first receiveoperation, a second transmit operation, a second receive operation, andan estimate operation. In the first transmit operation, the BSStransmits, to the SGSN, a BSSGP POSITION-COMMAND PDU which includes (i)a RRLP PDU, wherein the RRLP PDU includes a RRLP MTA Request messageintended for the target wireless device, and (ii) an indicator that thetarget wireless device is to perform a MTA procedure. In the firstreceive operation, the BSS receives, from the SGSN, a BSSGP DL-UNITDATAPDU which includes an LLC PDU intended for the target wireless device,wherein the LLC PDU includes the RRLP PDU, wherein the RRLP PDU furtherincludes the RRLP MTA Request Message. In the second transmit operation,the BSS transmits, to the target wireless device, the LLC PDU whichincludes the RRLP PDU which further includes the RRLP MTA RequestMessage. In the second receive operation, the BSS in response totransmitting the LLC PDU receives a PACCH acknowledgment from the targetwireless device. In the estimate operation, the BSS when receiving thePACCH acknowledgment estimates timing advance information associatedwith the PACCH acknowledgment, wherein the BSS is informed of a need toestimate the timing advance information when receiving the PACCHacknowledgment by a flag within the BSSGP DL-UNITDATA PDU. An exemplaryadvantage of the BSS implementing these operations is that the BSS isinformed that it is to estimate timing advance information whenreceiving a PACCH acknowledgment from the wireless device after the BSStransmits the LLC PDU to the wireless device.

In still yet another aspect, the present disclosure provides a method ina BSS configured to interact with a SGSN and a target wireless device.The method comprises a first transmitting step, a first receiving step,a second transmitting step, a second receiving step, and an estimatingstep. In the first transmitting step, the BSS transmits, to the SGSN, aBSSGP POSITION-COMMAND PDU which includes (i) a RRLP PDU, wherein theRRLP PDU includes a RRLP MTA Request message intended for the targetwireless device, and (ii) an indicator that the target wireless deviceis to perform a MTA procedure. In the first receiving step, the BSSreceives, from the SGSN, a BSSGP DL-UNITDATA PDU which includes a LLCPDU intended for the target wireless device, wherein the LLC PDUincludes the RRLP PDU, wherein the RRLP PDU further includes the RRLPMTA Request Message. In the second transmitting step, the BSS transmits,to the target wireless device, the LLC PDU which includes the RRLP PDUwhich further includes the RRLP MTA Request Message. In the secondreceiving step, the BSS in response to transmitting the LLC PDU receivesa PACCH acknowledgment from the target wireless device. In theestimating step, the BSS when receiving the PACCH acknowledgmentestimates timing advance information associated with the PACCHacknowledgment, wherein the BSS is informed of a need to estimate thetiming advance information when receiving the PACCH acknowledgment by aflag within the BSSGP DL-UNITDATA PDU. An exemplary advantage of the BSSimplementing these steps is that the BSS is informed that it is toestimate timing advance information when receiving PACCH acknowledgmentfrom the wireless device after the BSS transmits the LLC PDU to thewireless device.

In another aspect, the present disclosure provides a wireless deviceconfigured to interact with a BSS. The wireless device comprises aprocessor and a memory that stores processor-executable instructions,wherein the processor interfaces with the memory to execute theprocessor-executable instructions, whereby the wireless device isoperable to perform a receive operation, and a transmit operation. Inthe receive operation, the wireless device receives, from the BSS, a LLCPDU, wherein the LLC PDU includes a RRLP PDU, wherein the RRLP PDUfurther includes a RRLP MTA Message which indicates that the wirelessdevice does not need to perform a MTA procedure in a serving cell (i.e.,the cell in which the wireless device receives the RRLP MTA Message). Inthe transmit operation, the wireless device in response to receiving theLLC PDU, transmits a PACCH acknowledgment to the BSS. An exemplaryadvantage of the wireless device implementing these operations is thatthe wireless device reduces its battery consumption because the wirelessdevice does not need to perform the MTA procedure in the serving cell.

In yet another aspect, the present disclosure provides a method in awireless device configured to interact with a BSS. The method comprisesa receiving step, and a transmitting step. In the receiving step, thewireless device receives, from the BSS, a LLC PDU, wherein the LLC PDUincludes a RRLP PDU, wherein the RRLP PDU further includes a RRLP MTA

Request Message which indicates that the wireless device does not needto perform a MTA procedure in a serving cell (i.e., the cell in whichthe wireless device receives the RRLP MTA Message). In the transmittingstep, the wireless device in response to receiving the LLC PDU,transmits a PACCH acknowledgment to the BSS. An exemplary advantage ofthe wireless device implementing these steps is that the wireless devicereduces its battery consumption because the wireless device does notneed to perform the MTA procedure in the serving cell.

Additional aspects of the present disclosure will be set forth, in part,in the detailed description, figures and any claims which follow, and inpart will be derived from the detailed description, or can be learned bypractice of the invention. It is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory only and are not restrictive of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure may be obtainedby reference to the following detailed description when taken inconjunction with the accompanying drawings:

FIG. 1 (PRIOR ART) is a diagram illustrating a Multilateration processinvolving three base transceiver stations associated with three timingadvance (TA) values for a particular wireless device;

FIGS. 2A-2B (PRIOR ART) are an illustration of a Multilaterationprocedure for determining a position of a wireless device;

FIG. 3 is a diagram of an exemplary wireless communication network whichincludes a SGSN, multiple BSSs, and multiple wireless devices which areconfigured in accordance with an embodiment of the present disclosure;

FIGS. 4A-4B are an illustration of a Multilateration Positioningprocedure for determining a position of a wireless device in accordancewith an embodiment of the present disclosure;

FIGS. 5A-5B illustrate the contents of a BSSGP DL-UNITDATA PDU with aMessage Indicator Information Element in accordance with an embodimentof the present disclosure;

FIG. 6 is a diagram illustrating one possible coding of the MessageIndicator Information Element in accordance with an embodiment of thepresent disclosure;

FIG. 7 is a diagram illustrating one possible coding of a MessageIndicator Field in the Message Indicator Information Element shown inFIG. 6 in accordance with an embodiment of the present disclosure;

FIG. 8 is a diagram that illustrates the content of a BSSGPPOSITION-COMMAND PDU modified to include a Multilateration TimerInformation Element (IE) in accordance with an embodiment of the presentdisclosure;

FIG. 9 is a diagram that illustrates the content of the MultilaterationTimer IE which includes a MPM timer value in accordance with anembodiment of the present disclosure;

FIG. 10 is a diagram that illustrates the content of a modified RRLPFlags IE which includes a MPM timer value in accordance with anembodiment of the present disclosure;

FIG. 11 is a flowchart of a method implemented in the SGSN in accordancewith an embodiment of the present disclosure;

FIG. 12 is a block diagram illustrating a structure of the SGSNconfigured in accordance with an embodiment of the present disclosure;

FIG. 13 is a flowchart of a method implemented in the BSS in accordancewith an embodiment of the present disclosure;

FIG. 14 is a block diagram illustrating a structure of the BSSconfigured in accordance with an embodiment of the present disclosure;

FIG. 15 is a flowchart of a method implemented in the wireless device inaccordance with an embodiment of the present disclosure; and,

FIG. 16 is a block diagram illustrating a structure of the wirelessdevice configured in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

A discussion is provided first herein to describe an exemplary wirelesscommunication network that includes a CN node (e.g., SGSN, MME),multiple RAN nodes (e.g., BSSs, NodeBs, eNodeBs), and multiple wirelessdevices (e.g., mobile stations, IoT devices) in accordance with anembodiment of the present disclosure (see FIG. 3). Then, a discussion isprovided to disclose various techniques that the CN node (e.g., SGSN,MME), the RAN node (e.g., BSS, NodeB, eNodeB), and the wireless devicecan implement such that the RAN node is able to estimate a TimingAdvance value for the serving cell of the wireless device upon receiptof an acknowledgment message (e.g., PACCH acknowledgment, EC-PACCHacknowledgment from the wireless device (see FIGS. 4A-10). Thereafter, adiscussion is provided to explain the basicfunctionalities-configurations of the CN node (e.g., SGSN, MME), the RANnode (e.g., BSS, NodeB, eNodeB), and the wireless device in accordancewith different embodiments of the present disclosure (see FIGS. 11-16).

Exemplary Wireless Communication Network 300

Referring to FIG. 3, there is illustrated an exemplary wirelesscommunication network 300 in accordance with the present disclosure. Thewireless communication network 300 includes a core network 306 (whichcomprises at least one CN node 307) and multiple RAN nodes 302 ₁ and 302₂ (only two shown) which interface with multiple wireless devices 304 ₁,304 ₂, 304 ₃ . . . 304 _(n). The wireless communication network 300 alsoincludes many well-known components, but for clarity, only thecomponents needed to describe the features of the present disclosure aredescribed herein. Further, the wireless communication network 300 isdescribed herein as being a GSM/EGPRS wireless communication network 300which is also known as an EDGE wireless communication network 300.However, those skilled in the art will readily appreciate that thetechniques of the present disclosure which are applied to the GSM/EGPRSwireless communication network 300 are generally applicable to othertypes of wireless communication systems, including, for example, WCDMA,LTE, and WiMAX systems.

The wireless communication network 300 includes the RAN nodes 302 ₁ and302 ₂ (wireless access nodes—only two shown) which provide networkaccess to the wireless devices 304 ₁, 304 ₂, 304 ₃ . . . 304 _(n). Inthis example, the RAN node 302 ₁ is providing network access to wirelessdevice 304 ₁ while the RAN node 302 ₂ is providing network access towireless devices 304 ₂, 304 ₃ . . . 304 _(n). The RAN nodes 302 ₁ and302 ₂ are connected to the core network 306 (e.g., SGSN core network306) and, in particular, to the CN node 307 (e.g., SGSN 307). The corenetwork 306 is connected to an external packet data network (PDN) 308,such as the Internet, and a server 310 (only one shown). The wirelessdevices 304 ₁, 304 ₂, 304 ₃ . . . 304 n may communicate with one or moreservers 309 (only one shown) connected to the core network 306 and/orthe PDN 308. In this example, the RAN node 302 ₂ and the CN node 307 areboth connected to a positioning server 311 (e.g., Serving MobileLocation Center 311). The other RAN node 302 ₂ can be connected to thesame positioning server 311 (e.g., Serving Mobile Location Center 311)or to a different positioning server 311 (e.g., Serving Mobile LocationCenter 311).

The wireless devices 304 ₁, 304 ₂, 304 ₃ . . . 304 _(n) may refergenerally to an end terminal (user) that attaches to the wirelesscommunication network 300, and may refer to either a MTC device (e.g., asmart meter) or a non-MTC device. Further, the term “wireless device” isgenerally intended to be synonymous with the term mobile device, mobilestation (MS). “User Equipment,” or UE, as that term is used by 3GPP, andincludes standalone wireless devices, such as terminals, cell phones,smart phones, tablets, cellular IoT devices, IoT devices, andwireless-equipped personal digital assistants, as well as wireless cardsor modules that are designed for attachment to or insertion into anotherelectronic device, such as a personal computer, electrical meter, etc.

Likewise, unless the context clearly indicates otherwise, the term RANnode 302 ₁ and 302 ₂ (wireless access node 302 ₁ and 302 ₂) is usedherein in the most general sense to refer to a base station subsystem(BSS), a wireless access node, or a wireless access point in a wirelesscommunication network 300, and may refer to RAN nodes 302 ₁ and 302 ₂that are controlled by a physically distinct radio network controller aswell as to more autonomous access points, such as the so-called evolvedNode Bs (eNodeBs) in Long-Term Evolution (LTE) networks.

Each wireless device 304 ₁, 304 ₂, 304 ₃ . . . 304 _(n) may include atransceiver circuit 310 ₁, 310 ₂, 310 ₃ . . . 310 n for communicatingwith the RAN nodes 302 ₁ and 302 ₂, and a processing circuit 312 ₁, 312₂, 312 ₃ . . . 312 _(n) for processing signals transmitted from andreceived by the transceiver circuit 310 ₁, 310 ₂, 310 ₃ . . . 310 _(n)and for controlling the operation of the corresponding wireless device304 ₁, 304 ₂, 304 ₃ . . . 304 _(n). The transceiver circuit 310 ₁, 310₂, 310 ₃ . . . 310 _(n) may include a transmitter 314 ₁, 314 ₂, 314 ₃ .. . 314 _(n) and a receiver 316 ₁, 316 ₂, 316 ₃ . . . 316 _(n), whichmay operate according to any standard, e.g., the GSM/EDGE standard. Theprocessing circuit 312 ₁, 312 ₂, 312 ₃ . . . 312 _(n) may include aprocessor 318 ₁, 318 ₂, 318 ₃ . . . 318 _(n) and a memory 320 ₁, 320 ₂,320 ₃ . . . 320 _(n) for storing program code for controlling theoperation of the corresponding wireless device 304 ₁, 304 ₂, 304 ₃ . . .304 _(n). The program code may include code for performing theprocedures as described hereinafter.

Each RAN node 302 ₁ and 302 ₂ (BSS 302 ₁ and 302 ₂) may include atransceiver circuit 322 ₁ and 322 ₂ for communicating with wirelessdevices 304 ₁, 304 ₂, 304 ₃ . . . 304 _(n), a processing circuit 324 ₁and 324 ₂ for processing signals transmitted from and received by thetransceiver circuit 322 ₁ and 322 ₂ and for controlling the operation ofthe corresponding RAN node 302 ₁ and 302 ₂, and a network interface 326₁ and 326 ₂ for communicating with the core network 306. The transceivercircuit 322 ₁ and 322 ₂ may include a transmitter 328 ₁ and 328 ₂ and areceiver 330 ₁ and 330 ₂, which may operate according to any standard,e.g., the GSM/EDGE standard. The processing circuit 324 ₁ and 324 ₂ mayinclude a processor 332 ₁ and 332 ₂, and a memory 334 ₁ and 334 ₂ forstoring program code for controlling the operation of the correspondingRAN node 302 ₁ and 302 ₂. The program code may include code forperforming the procedures as described hereinafter.

The CN node 307 (e.g., SGSN 307, MME 307) may include a transceivercircuit 336 for communicating with the RAN nodes 302 ₁ and 302 ₂, aprocessing circuit 338 for processing signals transmitted from andreceived by the transceiver circuit 336 and for controlling theoperation of the CN node 307, and a network interface 340 forcommunicating with the RAN nodes 302 ₁ and 302 ₂. The transceivercircuit 336 may include a transmitter 342 and a receiver 344, which mayoperate according to any standard, e.g., the GSM/EDGE standard. Theprocessing circuit 338 may include a processor 346 and a memory 348 forstoring program code for controlling the operation of the CN node 307.The program code may include code for performing the procedures asdescribed hereinafter.

Techniques for Enabling the RAN Node 302 ₂ (for Example) to Estimate aTiming Advance Value

As discussed in the Background Section, at the 3GPP TSG-RANG Meeting #3it had been proposed (but no solutions presented) that in FIG. 2B's step11 the BSS 108 should also be able to estimate the Timing Advance value212 in the serving cell on reception of the (Extended Coverage-) PacketAssociated Control Channel ((EC-)PACCH) Packet Downlink Ack 214. Then,the BSS 108 could send at FIG. 2B's step 12 the estimated timing advance212 along with the BTS receiver accuracy and MS accuracy parameters(shown as MS accuracy information 216) to the SMLC 110 to update theserving cell related timing estimation, thereby allowing the MS 104 toleave the serving cell to perform the Multilateration Timing Advanceprocedure in additional cells without first performing theMultilateration Timing Advance procedure in the serving cell (recall:that the BTS receiver accuracy that is passed to the SMLC 110 as part ofthe MS accuracy information 216 is information that the BSS 108 is ableto self-generate (i.e., the BTS receiver accuracy portion of the MSaccuracy information 216 is not passed from the wireless device 104 tothe BSS 108)). As discussed below, the inventors have determined whyFIG. 2's steps 11-12 was not possible in the past and also havedetermined various techniques that when implemented enable the BSS toperform FIG. 2B's steps 11-12.

The problem with the prior art process can be seen with reference toFIG. 2B's step 10 where the triggering RRLP PDU (which contains a RRLPMTA Request message) transmitted by the SGSN 112 to the BSS 108 is in anLLC PDU which is inside a BSSGP DL-UNITDATA PDU, however the LLC PDU(which contains the RRLP PDU which contains the RRLP MTA Requestmessage) is sent transparently through the BSS 108 to the MS 104. Hence,the BSS 108 which transparently sent the LLC PDU (which contains theRRLP PDU which contains the RRLP MTA Request message) over the radiointerface to the wireless device in FIG. 2B's step 10 will not know thatit should use algorithms (e.g., enhanced algorithms such as oversamplingand interpolation) for estimating the Timing Advance value uponreceiving one or more (EC-) PACCH Packet Downlink Ack messages from thewireless device in FIG. 2B's step 11. The various techniques that canaddress this problem are discussed next.

In the present disclosure with reference to FIGS. 4A-4B, the SGSN 307upon receiving a BSSGP POSITION-COMMAND PDU 400 from the BSS 302 ₂ inFIG. 4B's step 9b is aware that it has been requested to forward a RRLPPDU 402 (containing a RRLP MTA Request message 404) to the wirelessdevice 304 ₃ (for example) because an indicator 520, 535 that the targetwireless device 304 ₃ is to perform a MTA procedure is also included inthe BSSGP POSITION-COMMAND PDU 400 (note: this new indicator 520, 535 isdiscussed in more detail below). Then, the SGSN 307 maps the RRLP PDU402 (containing the RRLP MTA Request message 404) into an LLC PDU 406and forwards the LLC PDU 406 (containing the RRLP PDU 402 which containsthe RRLP MTA Request message 404) to the same BSS 302 ₂ using a BSSGPDL-UNITDATA PDU 410 as shown in FIG. 4B's step 10. The BSS 302 ₂ thenrelays the LLC PDU 406 (containing the RRLP PDU 402 which contains theRRLP MTA Request message 404) to the target wireless device 304 ₃ overthe radio interface. To ensure that the BSS 302 ₂ is aware that thereceived BSSGP DL-UNITDATA PDU 410 contains the RRLP PDU 402 (containingthe RRLP MTA Request message 404) inside the LLC PDU 406, it is proposedto enhance the BSSGP DL-UNITDATA PDU 410 with a flag 420 that providesthis indication. The flag 420 may be:

-   -   a new Information Element (IE) 420 a (referred to herein as        Message Indicator IE 420 a) within the BSSGP DL-UNITDATA PDU        410, or,    -   a spare code point in some other legacy IE within the BSSGP        DL-UNITDATA PDU 410.

The BSS 302 ₂ upon reception of the enhanced BSSGP DL-UNITDATA PDU 410containing the new flag 420 can estimate the serving cell's TimingAdvance by invoking advanced Timing Advance estimation algorithms suchas oversampling and interpolation on the one or more PACCH PacketDownlink Acks 422 ((EC-)PACCH Packet Downlink Acks 422) received fromthe wireless device 304 ₃ after sending the wireless device 304 ₃ theLLC PDU 406 (containing the RRLP PDU 402 which contains the RRLP MTARequest message 404) using a downlink Temporary Block Flow (TBF)(EC-TBF)(see FIG. 4B's step 11). It should be appreciated that the BSS302 ₂ sends the wireless device 304 ₃ an EC Downlink Assignment messageto establish a downlink TBF which is then used to deliver the LLC PDU406 to the wireless device 304 ₃. When the EC Downlink Assignmentmessage includes the “Multilateration Information Request” IE (seesection 9.1.64 of 3GPP TS 44.018 v14.0.0 dated Dec. 23, 2016—thecontents of which are incorporated herein by reference for all purposes)it serves to inform the wireless device 304 ₃ that it is to include “MSTransmission Offset” and “MS Sync Accuracy” information in the one ormore PACCH acknowledgments 422 that the wireless device 304 ₃ sends inresponse to receiving the LLC PDU 406, i.e., even though the BSS 302 ₂is informed of a need to estimate the timing advance information usingadvanced procedures by the flag 420 within the BSSGP DL-UNITDATA PDU 410per FIG. 4B's step 10, the BSS 302 ₂ will not be able to actuallyperform the advanced procedures unless it first uses the“Multilateration Information Request” IE to tell the wireless device 304₃ to include “MS Transmission Offset” and “MS Sync Accuracy” informationin the one or more PACCH acknowledgments 422 (note: the inclusion of the“Multilateration Information Request” IE in the EC Downlink Assignmentis covered by prior art). Thereafter, the BSS 302 ₂ sends the estimatedserving cell's Timing Advance along with the Accuracy Information 415 tothe SMLC 311 via a BSSMAP Connection Oriented Message 424 (see FIG. 4B'sstep 12) (note: the BSSMAP Connection Oriented Message 424 may alsoidentify the BTS that received the Packet Associated Control Channel(PACCH) acknowledgment 422 from the target wireless device 304 ₃).

In one embodiment, to ensure that the BSS 302 ₂ is aware that the BSSGPDL-UNITDATA PDU 410 contains a RRLP PDU 402 (which contains a RRLPMultilateration Timing Advance Request message 404) inside an LLC PDU406, it has been proposed to add the aforementioned new informationelement 420 a referred to herein as the Message Indicator IE 420 a tothe BSSGP DL-UNITDATA PDU 410. FIGS. 5A-5B are a table illustrating thecontent of the BSSGP DL-UNITDATA PDU 410 which includes the legacy IEs(e.g., the LLC PDU 406) and the new Message Indicator 420 a (note: thistable including the new Message Indicator 420 a and the associated note16 or similar could be added to the 3GPP TS 48.018). FIG. 6 is a diagramillustrating an exemplary coding of the Message Indicator IE 420 a. FIG.7 is a diagram illustrating an exemplary coding of a message indicatorfield 424 (octet 3) in the Message Indicator IE 420 a where the messageindicator 424 will specifically indicate to the BSS 302 ₂ that a RRLPMultilateration Timing Advance Request message 404 is included insidethe LLC PDU 406. It should also be noted that through the introductionof a more generic field like the Message Indicator field 424, that thisgeneric field may be used to indicate the inclusion of any other higherlayer message through the use of remaining available code points. Forexample, if there is a new positioning method for which it will bebeneficial for a BSS 302 ₂ (for example), when relaying a LLC PDU 406(containing a RRLP message) to a target wireless device 304 ₃ for thatnew positioning method, to be made aware of then this can beaccomplished by using the new Message Indicator field 424 described inthe present disclosure.

The SGSN 307 needs to know that the target wireless device 304 ₃ isbeing requested to perform a MTA positioning procedure before the SGSN307 is able to generate and transmit the BSSGP DL-UNITDATA PDU 410 whichincludes (i) the LLC PDU 406 (which includes the RRLP PDU 402 whichincludes the RRLP MTA Request message 404), and (ii) the flag 420 whichindicates to the BSS 302 ₂ that it needs to estimate TA information 413when receiving a PACCH acknowledgment 422 from the target wirelessdevice 304 ₃ (see FIG. 4B's step 10). To ensure that the SGSN 307 knowsthat the target wireless device 304 ₃ is being requested to perform aMTA positioning procedure (and not some other positioning procedure) sothat the SGSN 307 can then transmit the BSSGP DL-UNITDATA PDU 410 to theBSS 302 ₂ the following can be done: the BSS 302 ₂ can send the SGSN 307a BSSGP POSITION-COMMAND PDU 400 which not only includes the RRLP PDU402 (containing the RRLP MTA Request message 404) but also includes anindicator 520, 535 that the target wireless device 304 ₃ is to perform aMTA procedure (see FIG. 4B's step 9b). In particular, the BSS 302 ₂ canuse any one of several different techniques to generate this BSSGPPOSITION-COMMAND PDU 400 which contains the indication 520, 535 (whichcan be in the form of a flag or a timer) that a given wireless device304 ₃ (for example) is going perform the MTA procedure. These exemplaryseveral different techniques are discussed in detail in more detailbelow.

In a first technique, to ensure that the SGSN 307 is aware that a RRLPMTA Request message 404 is being sent to a given wireless device 304 ₃(for example), the BSSGP POSITION-COMMAND PDU 400 sent by the BSS 302 ₂to the SGSN 307 is enhanced with a new Multilateration Timer IE 520 thatprovides the SGSN 307 with an indication 522 that the BSSGPPOSITION-COMMAND PDU 400 is associated with a given wireless device 304₃ (for example) that is going perform the MTA procedure. In its simplestform the new Multilateration Timer IE 520 may have an indication 522which is a single bit flag. In addition, this indication 522 can triggerthe SGSN 307 to start a timer 508 (e.g., MTA timer 508). In exemplaryapplications, the MTA timer 508 can be used by the SGSN 307 to (a)suspend downlink data delivery to the wireless device 304 ₃ while thewireless device 304 ₃ is performing the MTA procedure (b) guard againstthe SGSN 307 being asked to start another MTA positioning procedure withthe wireless device 304 ₃ (for example) by sending a paging message tothe wireless device 304 ₃ while the wireless device 304 ₃ already has anongoing MTA positioning procedure, and (c) allow the SGSN 307 to knowthe maximum time that it should allow for the MTA positioning procedureto be completed by the wireless device 304 ₃.

In a second technique, to ensure that the SGSN 307 is aware that a RRLPMTA Request message 404 is being sent to a given wireless device 304 ₃(for example), the BSSGP POSITION-COMMAND PDU 400 sent by the BSS 302 ₂to the SGSN 307 is enhanced with a new Multilateration Timer IE 520 thatnot only indicates to the SGSN 307 that the BSSGP POSITION-COMMAND PDU400 is associated with a given wireless device 304 ₃ (for example) thatis going perform the MTA procedure but also provides the SGSN 307 with atimer value 509 (e.g., MPM timer value 509) which is used to set the MTAtimer 508. In exemplary applications, the MTA timer 508 can be used bythe SGSN 307 to (a) suspend downlink data delivery to the wirelessdevice 304 ₃ while the wireless device 304 ₃ is performing the MTAprocedure (b) guard against the SGSN 307 being asked to start anotherMTA positioning procedure with the wireless device 304 ₃ (for example)by sending a paging message to the wireless device 304 ₃ while thewireless device 304 ₃ already has an ongoing MTA positioning procedure,and (c) allow the SGSN 307 to know the maximum time that it should allowfor the MTA positioning procedure to be completed by the wireless device304 ₃. The timer value 509 which is provided in the new MultilaterationTimer IE 520 to the SGSN 307 is the same timer value which is associatedwith a Multilateration Positioning Method (MPM) timer 530 that the SMLC311 transmits in a BSSMAP-LE CONNECTION ORIENTED INFORMATION message 504(see FIG. 4A's step 9a) to the serving BSS 302 ₂ (for example) for thepurpose of knowing how long the Signalling Connection Control Part(SCCP) connection across the Lb interface shall be maintained (note: theLb interface is between the SMLC 311 and the BSS 302 ₂). FIG. 8 is adiagram that illustrates the content of the BSSGP POSITION-COMMAND PDU400 modified to include the new Multilateration Timer IE 520. FIG. 9 isa diagram that illustrates the content of the new Multilateration TimerIE 520 which includes the MPM timer value 509.

In a third technique, to ensure that the SGSN 307 is aware that a RRLPMTA Request message 404 is being sent to a given wireless device 304 ₃(for example), the BSSGP POSITION-COMMAND PDU 400 sent by the BSS 302 ₂to the SGSN 307 is enhanced where a RRLP Flags IE 535 is modified to notonly indicate to the SGSN 307 that the BSSGP POSITION-COMMAND PDU 400 isassociated with a given wireless device 304 ₃ (for example) that isgoing perform the MTA procedure but also provides the SGSN 307 with atimer value 509 which is used to set the MTA timer 508. The timer value509 which is provided in the RRLP Flags IE 535 to the SGSN 307 is thesame timer value 509 which is associated with a MultilaterationPositioning Method (MPM) timer 530 that the SMLC 311 provides in theBSSMAP-LE CONNECTION ORIENTED INFORMATION message 504 (see FIG. 4A'sstep 9a) to the serving BSS 302 ₂ (for example). In the third technique,the RRLP Flags IE 535 is modified by the BSS 302 ₂ to include the sametimer value 509 as the Multilateration Positioning Method (MPM) timer530 which both the BSS 302 ₂ as well as the SGSN 307 can use during theMTA procedure for the given wireless device 304 ₃. The BSS 302 ₂ can usethe timer value 509 indicated by the RRLP Flags IE 535 to supervise theSCCP connection associated with the wireless device 304 ₃ (for example).The SGSN 307 can use the timer value 509 indicated by the RRLP Flags IE535 to suspend downlink data delivery and paging to the wireless device304 ₃ for the duration of the MTA timer 508 which is set based on thetimer value 509. FIG. 10 is a diagram that illustrates the content ofthe modified RRLP Flags IE 535 (note: the modified RRLP Flags IE 535which includes the MPM timer value 509 would be part of the BSSGPPOSITION-COMMAND PDU 400 which is shown in detail in FIG. 8).

The modified BSSGP POSITION-COMMAND PDU 400 and the aforementioned threetechniques are also described in the co-filed U.S. patent applicationSer. No. 15/886,616 entitled “Notification of Ongoing MultilaterationTiming Advance (MTA) Procedure to a Serving GPRS Support Node (SGSN)”,which claims the benefit of priority to U.S. Provisional ApplicationSer. No. 62/453,843, filed on Feb. 2, 2017. The entire contents of eachof these documents are hereby incorporated herein by reference for allpurposes.

Basic Functionalities-Configurations of SGSN 307, the BSS 302 ₂, and theWireless Device 304 ₃

Referring to FIG. 11, there is a flowchart of a method 1100 implementedin a SGSN 307 which is configured to interact with a BSS 302 ₂ inaccordance with an embodiment of the present disclosure. At step 1102,the SGSN 307 receives, from the BSS 302 ₂, a BSSGP POSITION-COMMAND PDU400 which includes a RRLP PDU 402, wherein the RRLP PDU 402 includes (i)a RRLP MTA Request message 404 intended for a target wireless device 304₃ (for example), and (ii) an indicator 520, 535 that the target wirelessdevice 304 ₃ is to perform a MTA procedure (see FIG. 4's step 9b). Atstep 1104, the SGSN 307 transmits, to the BSS 302 ₂, a BSSGP Down Link(DL)-UNITDATA PDU 410 which includes a LLC PDU 406 intended for thetarget wireless device 304 ₃, wherein the LLC PDU 406 includes the RRLPPDU 402, wherein the RRLP PDU 402 further includes the RRLP MTA Requestmessage 404, and wherein the BSSGP DL-UNITDATA PDU 410 further includesa flag 420 (e.g., Message Indicator IE 420 a, a code point 420 b in alegacy information element) which indicates to the BSS 302 ₂ a need toestimate timing advance information 413 when receiving a PacketAssociated Control Channel (PACCH) acknowledgment 422 from the targetwireless device (see FIG. 4's step 10).

Referring to FIG. 12, there is a block diagram illustrating structuresof an exemplary SGSN 307 in accordance with an embodiment of the presentdisclosure. In one embodiment, the SGSN 307 comprises a receive module1202 and a transmit module 1204. The receive module 1202 is configuredto receive, from the BSS 302 ₂, a BSSGP POSITION-COMMAND PDU 400 whichincludes (i) a RRLP PDU 402, wherein the RRLP PDU 402 includes a RRLPMTA Request message 404 intended for a target wireless device 304 ₃ (forexample), and (ii) an indicator 520, 535 that the target wireless device304 ₃ is to perform a MTA procedure (see FIG. 4's step 9b). The transmitmodule 1204 is configured to transmit, to the BSS 302 ₂, a BSSGP DownLink (DL)-UNITDATA PDU 410 which includes a LLC PDU 406 intended for thetarget wireless device 304 ₃, wherein the LLC PDU 406 includes the RRLPPDU 402, wherein the RRLP PDU 402 further includes the RRLP MTA Requestmessage 404, and wherein the BSSGP DL-UNITDATA PDU 410 further includesa flag 420 (e.g., Message Indicator IE 420 a, a code point 420 b in alegacy information element) which indicates to the BSS 302 ₂ a need toestimate timing advance information 413 when receiving a PacketAssociated Control Channel (PACCH) acknowledgment 422 from the targetwireless device (see FIG. 4's step 10). It should be noted that the SGSN307 may also include other components, modules or structures which arewell-known, but for clarity, only the components, modules or structuresneeded to describe the features of the present disclosure are describedherein.

As those skilled in the art will appreciate, the above-described modules1202 and 1204 of the SGSN 307 may be implemented separately as suitablededicated circuits. Further, the modules 1202 and 1204 can also beimplemented using any number of dedicated circuits through functionalcombination or separation. In some embodiments, the modules 1202 and1204 may be even combined in a single application specific integratedcircuit (ASIC). As an alternative software-based implementation, theSGSN 307 may comprise a memory 348, a processor 346 (including but notlimited to a microprocessor, a microcontroller or a Digital SignalProcessor (DSP), etc.) and a transceiver 336. The memory 348 storesmachine-readable program code executable by the processor 346 to causethe SGSN 307 to perform the steps of the above-described method 1100.

Referring to FIG. 13, there is a flowchart of a method 1300 implementedin a BSS 302 ₂ that is configured to interact with a SGSN 307 and atarget wireless device 304 ₃ in accordance with an embodiment of thepresent disclosure. At step 1302, the BSS 302 ₂, transmits, to the SGSN307, a BSSGP POSITION-COMMAND PDU 400 which includes (i) a RRLP PDU 402,wherein the RRLP PDU 402 includes a RRLP MTA Request message 404intended for the target wireless device 304 ₃, and (ii) an indicator520, 535 that the target wireless device 304 ₃ is to perform a MTAprocedure (see FIG. 4's step 9b). At step 1304, the BSS 302 ₂ receives,from the SGSN 307, a BSSGP DL-UNITDATA PDU 410 which includes a LLC PDU406 intended for the target wireless device 304 ₃, wherein the LLC PDU406 includes the RRLP PDU 402, wherein the RRLP PDU 402 further includesthe RRLP MTA Request Message 404 (see FIG. 4's step 10). At step 1306,the BSS 302 ₂ transmits, to the target wireless device 304 ₃, the LLCPDU 406, wherein the LLC PDU 406 includes the RRLP PDU 402, and whereinthe RRLP PDU 402 further includes the RRLP MTA Request message 404 (seeFIG. 4's step 10). At step 1308, the BSS 302 ₂ in response totransmitting the LLC PDU 406, receives a PACCH acknowledgment 422 (e.g.,EC-PACCH acknowledgment) from the target wireless device 304 ₃ (see FIG.4's step 10). At step 1310, the BSS 302 ₂ when receiving the PACCHacknowledgment 422, estimates (e.g., using at least one of anoversampling process and an interpolation process) timing advanceinformation 413 associated with the PACCH acknowledgment 422, whereinthe BSS 302 ₂ is informed of a need to estimate the timing advanceinformation 413 when receiving the PACCH acknowledgment 422 by a flag420 (e.g., Message Indicator IE 420 a, code point 420 b in a legacy IE)within the BSSGP DL-UNITDATA PDU 420 (see FIG. 4's step 11). At step1312, the BSS 302 ₂ can transmit, to a SMLC 311, a BSSMAP ConnectionOriented Message 424 which includes (i) the estimated timing advanceinformation 413; and (ii) accuracy information 415 (e.g., the MS SyncAccuracy associated with the target wireless device 304 ₃ and the BTSReceiver Accuracy associated with the BTS that receives the PACCHacknowledgment 422). It should be appreciated that the BSS 302 ₁ (andother BSSs) would also perform method 1300.

Referring to FIG. 14, there is a block diagram illustrating structuresof an exemplary BSS 302 ₂ in accordance with an embodiment of thepresent disclosure. In one embodiment, the BSS 302 ₂ comprises a firsttransmit module 1402, a first receive module 1404, a second transmitmodule 1406, a second receive module 1408, an estimate module 1410, andan optional third transmit module 1412. The first transmit module 1402is configured to transmit, to the SGSN 307, a BSSGP POSITION-COMMAND PDU400 which includes (i) a RRLP PDU 402, wherein the RRLP PDU 402 includesa RRLP MTA Request message 404 intended for the target wireless device304 ₃, and (ii) an indicator 520, 535 that the target wireless device304 ₃ is to perform a MTA procedure (see FIG. 4's step 9b). The firstreceive module 1404 is configured to receive, from the SGSN 307, a BSSGPDL-UNITDATA PDU 410 which includes a LLC PDU 406 intended for the targetwireless device 304 ₃, wherein the LLC PDU 406 includes the RRLP PDU402, wherein the RRLP PDU 402 further includes the RRLP MTA RequestMessage 404 (see FIG. 4's step 10). The second transmit module 1406 isconfigured to transmit, to the target wireless device 304 ₃, the LLC PDU406, wherein the LLC PDU 406 includes the RRLP PDU 402, and wherein theRRLP PDU 402 further includes the RRLP MTA Request message 404 (see FIG.4's step 10). The second receive module 1408 in response to thetransmission of the LLC PDU 406 is configured to receive a PACCHacknowledgment 422 (e.g., EC-PACCH acknowledgment) from the targetwireless device 304 ₃ (see FIG. 4's step 10). The estimate module 1410when receiving the PACCH acknowledgment 422 is configured to estimate(e.g., using at least one of an oversampling process and aninterpolation process) timing advance information 413 associated withthe PACCH acknowledgment 422, wherein the estimating module 1410 isinformed of a need to estimate the timing advance information 413 whenreceiving the PACCH acknowledgment 422 by a flag 420 (e.g., MessageIndicator IE 420 a, code point 420 b in a legacy IE) within the BSSGPDL-UNITDATA PDU 420 (see FIG. 4's step 11). The optional third transmitmodule 1412 can be configured to transmit, to the SMLC 311, a BSSMAPConnection Oriented Message 424 which includes (i) the estimated timingadvance information 413; and (ii) accuracy information 415 (e.g., the MSSync Accuracy associated with the target wireless device 304 ₃ and theBTS Receiver Accuracy associated with the BTS that receives the PACCHacknowledgment 422). It should be noted that the BSS 302 ₂ may alsoinclude other components, modules or structures which are well-known,but for clarity, only the components, modules or structures needed todescribe the features of the present disclosure are described herein.

As those skilled in the art will appreciate, the above-described modules1402, 1404, 1406, 1408, 1410, and 1412 may be implemented separately assuitable dedicated circuits. Further, the modules 1402, 1404, 1406,1408, 1410, and 1412 can also be implemented using any number ofdedicated circuits through functional combination or separation. In someembodiments, the modules 1402, 1404, 1406, 1408, 1410, and 1412 may beeven combined in a single application specific integrated circuit(ASIC). As an alternative software-based implementation, the BSS 302 ₂may comprise a memory 334 ₂, a processor 332 ₁ (including but notlimited to a microprocessor, a microcontroller or a Digital SignalProcessor (DSP), etc.) and a transceiver 322 ₂. The memory 334 ₂ storesmachine-readable program code executable by the processor 332 ₂ to causethe BSS 302 ₂ to perform the steps of the above-described method 1300.

Referring to FIG. 15, there is a flowchart of a method 1500 implementedin a wireless device 304 ₃ that is configured to interact with a BSS 302₂ in accordance with an embodiment of the present disclosure. At step1502, the wireless device 304 ₃ receives, from the BSS 302 ₂, a LLC PDU406, wherein the LLC PDU 406 includes a RRLP PDU 402, wherein the RRLPPDU 402 further includes a RRLP MTA Request Message 404 which indicatesthat the wireless device 304 ₃ does not need to perform aMultilateration Timing Advance procedure in a serving cell (see FIG. 4'sstep 10). At step 1504, the wireless device 304 ₃ in response toreceiving the LLC PDU 406, transmits a PACCH acknowledgment 422 (e.g.,EC-PACCH acknowledgment 422) to the BSS 302 ₂ (see FIG. 4's step 10). Itshould be appreciated that the other wireless devices 304 ₁, 304 ₂ . . .304 _(n) would also perform method 1500.

Referring to FIG. 16, there is a block diagram illustrating structuresof an exemplary wireless device 304 ₃ in accordance with an embodimentof the present disclosure. In one embodiment, the wireless device 304 ₃comprises a receive module 1602 and a transmit module 1604. The receivemodule 1602 is configured to receive, from the BSS 302 ₂, a LLC PDU 406,wherein the LLC PDU 406 includes a RRLP PDU 402, wherein the RRLP PDU402 further includes a RRLP MTA Request Message 404 which indicates thatthe wireless device 304 ₃ does not need to perform a MultilaterationTiming Advance procedure in a serving cell (see FIG. 4's step 10). Thetransmit module 1604 in response to receiving the LLC PDU 406 isconfigured to transmit a PACCH acknowledgment 422 (e.g., EC-PACCHacknowledgment 422) to the BSS 302 ₂ (see FIG. 4's step 10). It shouldbe noted that the wireless device 304 ₃ may also include othercomponents, modules or structures which are well-known, but for clarity,only the components, modules or structures needed to describe thefeatures of the present disclosure are described herein.

As those skilled in the art will appreciate, the above-described modules1602 and 1604 of the wireless device 304 ₃ may be implemented separatelyas suitable dedicated circuits. Further, the modules 1602 and 1604 canalso be implemented using any number of dedicated circuits throughfunctional combination or separation. In some embodiments, the modules1602 and 1604 may be even combined in a single application specificintegrated circuit (ASIC). As an alternative software-basedimplementation, the wireless device 304 ₃ may comprise a memory 320 ₃, aprocessor 318 ₃ (including but not limited to a microprocessor, amicrocontroller or a Digital Signal Processor (DSP), etc.) and atransceiver 310 ₃. The memory 320 ₃ stores machine-readable program codeexecutable by the processor 318 ₃ to cause the wireless device 304 ₃ toperform the steps of the above-described method 1500.

In view of the foregoing, it will be appreciated by those skilled in theart that an objective of the present disclosure is to enable the SGSN307 to provide the BSS 302 ₂ (for example) with an indication, e.g., inthe form of a flag 420, that the LLC PDU 406 sent to a given wirelessdevice 304 ₃ (for example) contains a RRLP Multilateration TimingAdvance Request message 404 such that the BSS 302 ₂ may invoke moreadvanced Timing Advance estimation algorithms for reception of thesubsequent uplink (EC-) PACCH acknowledgment block(s) 422 received fromthe wireless device 304 ₃. Recall: the BSS 302 ₂ sends the wirelessdevice 304 ₃ an EC Downlink Assignment message to establish a downlinkTBF which is then used to deliver the LLC PDU 406 to the wireless device304 ₃. When the EC Downlink Assignment message includes the“Multilateration Information Request” IE (see section 9.1.64 of 3GPP TS44.018 v14.0.0 dated Dec. 23, 2016-12-23—the contents of which areincorporated herein by reference for all purposes), it serves to informthe wireless device 304 ₃ that it is to include “MS Transmission Offset”and “MS Sync Accuracy” information in the one or more PACCHacknowledgments 422 that the wireless device 304 ₃ sends in response toreceiving the LLC PDU 406, i.e., even though the BSS 302 ₂ is informedof a need to estimate the timing advance information using advancedprocedures by the flag 420 within the BSSGP DL-UNITDATA PDU 410 per FIG.4B's step 10, the BSS 302 ₂ will not be able to actually perform theadvanced procedures unless it first uses the “MultilaterationInformation Request” IE to tell the wireless device 304 ₃ to include “MSTransmission Offset” and “MS Sync Accuracy” information in the one ormore PACCH acknowledgments 422 (note: the inclusion of the“Multilateration Information Request” IE in the EC Downlink Assignmentis covered by prior art). An advantage with the proposed solution isthat the BSS 302 ₂ will know when a triggering RRLP PDU 402 (containinga RRLP Multilateration Timing Advance Request message 404) is includedwithin a LLC PDU 406 received within a BSSGP DL-UNITDATA PDU 410 fromthe SGSN 307 and thus the BSS 302 ₂ now knows it should invoke moreadvanced Timing Advance estimation algorithms when receiving one or more(EC-)PACCH Packet Downlink Acks 422 from the wireless device 304 ₃ aftersending the wireless device 304 ₃ the LLC PDU 406. This in turn has thefollowing advantages:

-   -   The RRLP Multilateration Timing Advance Request message 404 sent        to the wireless device 304 ₃ can avoid indicating the need for        the wireless device 304 ₃ to perform the Multilateration Timing        Advance procedure using the serving cell since the BSS 302 ₂        will acquire the necessary Timing Advance value, the BTS        receiver accuracy and the wireless device 304 ₃'s accuracy        parameter and forward them to the SMLC 311 (see FIG. 4B's step        12). This helps to limit battery consumption in the wireless        device 304 ₃.    -   Avoiding the wireless device 304 ₃ having to perform the        Multilateration Timing Advance procedure in the serving cell        after the BSS 302 ₂ has successfully sent the RRLP PDU 402        (containing a RRLP Multilateration Timing Advance Request        message 404) to the wireless device 304 ₃ will reduce processing        load in the BSS 302's BTS.

It should be appreciated that in the above described embodiments thatthese embodiments are exemplary and not mutually exclusive. For example,components from one embodiment may be tacitly assumed to be present inanother embodiment and it will be obvious to a person skilled in the arthow those components may be used in the other exemplary embodiments.

The exemplary embodiments described herein have been exemplified withGlobal System for Mobile telephony (GSM)/Enhanced Data rates for GSMEvolution (EDGE) as the communications network 300. The core networknode 307 has been exemplified herein as being a Serving GPRS SupportNode (SGSN) 307, but generally the core network node 307 may be any typeof core network node that is serving the wireless device as well. Forexample, for NB-IoT the applicable core network node 307 may also be aMobility Management Entity (MME). The radio access network node 302 ₂(controller node 302 ₂) has been exemplified herein as being a BSS 302 ₂but generally the radio access network node 302 ₂ may be any type ofradio access network node 302 ₂ that is serving the wireless device aswell. The positioning node 311 has been exemplified herein as being aSMLC node 311 but may, e.g., for NB-IoT be an Evolved Serving MobileLocation Center (E-SMLC) node 311.

It should further be noted that, to anyone skilled in the art, there areseveral realizations of the embodiments described herein withprincipally equivalent functionality where e.g., introduced fields maybe longer or shorter or coded in a different way. In addition, it shouldbe noted that message names, parameters, and information elements maychange during the course of the specification work, which implies thee.g., message names such as RRLP MULTILATERATION REQUEST message andRRLP Positioning Multilateration Timing Advance message shall beconsidered to be equivalent. This principle also applies to othermessages, parameters, and information element names used herein so longas the principal use/function remain the same.

Those skilled in the art will appreciate that the use of the term“exemplary” is used herein to mean “illustrative,” or “serving as anexample,” and is not intended to imply that a particular embodiment ispreferred over another or that a particular feature is essential.Likewise, the terms “first” and “second,” and similar terms, are usedsimply to distinguish one particular instance of an item or feature fromanother, and do not indicate a particular order or arrangement, unlessthe context clearly indicates otherwise. Further, the term “step,” asused herein, is meant to be synonymous with “operation” or “action.” Anydescription herein of a sequence of steps does not imply that theseoperations must be carried out in a particular order, or even that theseoperations are carried out in any order at all, unless the context orthe details of the described operation clearly indicates otherwise.

Of course, the present disclosure may be carried out in other specificways than those herein set forth without departing from the scope andessential characteristics of the invention. One or more of the specificprocesses discussed above may be carried out in a cellular phone orother communications transceiver comprising one or more appropriatelyconfigured processing circuits, which may in some embodiments beembodied in one or more application-specific integrated circuits(ASICs). In some embodiments, these processing circuits may comprise oneor more microprocessors, microcontrollers, and/or digital signalprocessors programmed with appropriate software and/or firmware to carryout one or more of the operations described above, or variants thereof.In some embodiments, these processing circuits may comprise customizedhardware to carry out one or more of the functions described above. Thepresent embodiments are, therefore, to be considered in all respects asillustrative and not restrictive.

Although multiple embodiments of the present disclosure have beenillustrated in the accompanying Drawings and described in the foregoingDetailed Description, it should be understood that the invention is notlimited to the disclosed embodiments, but instead is also capable ofnumerous rearrangements, modifications and substitutions withoutdeparting from the present disclosure that as has been set forth anddefined within the following claims.

1. A Serving GPRS Support Node (SGSN) configured to interact with a BaseStation Subsystem (BSS), the SGSN comprising: a processor; and, a memorythat stores processor-executable instructions, wherein the processorinterfaces with the memory to execute the processor-executableinstructions, whereby the SGSN is operable to: transmit, to the BSS, aBSS General Packet Radio Service (GPRS) Protocol (BSSGP) Down Link(DL)-UNITDATA Packet Data Unit (PDU) which includes a Logical LinkControl (LLC) PDU intended for a target wireless device, wherein the LLCPDU includes a Radio Resource Location Services Protocol (RRLP) PDU,wherein the RRLP PDU further includes a RRLP Multilateration TimingAdvance (MTA) Request Message, wherein the BSSGP DL-UNITDATA PDU furtherincludes a flag which indicates to the BSS a need to acquire timingadvance information.
 2. The SGSN of claim 1, wherein the flag is a codepoint in an information element.
 3. A method implemented in a ServingGPRS Support Node (SGSN) configured to interact with a Base StationSubsystem (BSS), the method comprising: transmitting, to the BSS, a BSSGeneral Packet Radio Service (GPRS) Protocol (BSSGP) Down Link(DL)-UNITDATA Packet Data Unit (PDU) which includes a Logical LinkControl (LLC) PDU intended for a target wireless device, wherein the LLCPDU includes a Radio Resource Location Services Protocol (RRLP) PDU,wherein the RRLP PDU further includes a RRLP Multilateration TimingAdvance (MTA) Request Message, wherein the BSSGP DL-UNITDATA PDU furtherincludes a flag which indicates to the BSS a need to acquire timingadvance information.
 4. The method of claim 3, wherein the flag is acode point in an information element.
 5. A Base Station Subsystem (BSS)configured to interact with a Serving GPRS Support Node (SGSN) and atarget wireless device, the BSS comprising: a processor; and, a memorythat stores processor-executable instructions, wherein the processorinterfaces with the memory to execute the processor-executableinstructions, whereby the BSS is operable to: receive, from the SGSN, aBSS General Packet Radio Service (GPRS) Protocol (BSSGP) Down Link(DL)-UNITDATA Packet Data Unit (PDU) which includes a Logical LinkControl (LLC) PDU intended for the target wireless device, wherein theLLC PDU includes a Radio Resource Location Services Protocol (RRLP) PDU,wherein the RRLP PDU further includes a RRLP Multilateration TimingAdvance (MTA) Request message; transmit, to the target wireless device,the LLC PDU which includes the RRLP PDU, wherein the RRLP PDU furtherincludes the RRLP MTA Request Message; receive a Packet AssociatedControl Channel (PACCH) acknowledgment from the target wireless device;and, acquire timing advance information associated with the PACCHacknowledgment, wherein the BSS is informed of a need to acquire thetiming advance information by a flag within the BSSGP DL-UNITDATA PDU.6. The BSS of claim 5, wherein the flag is a code point in aninformation element.
 7. The BSS of claim 5, wherein the BSS is furtheroperable to transmit, to a Serving Mobile Location Center (SMLC), aBSSMAP Connection Oriented Message which includes (i) the acquiredtiming advance information; and (ii) accuracy information associatedwith the target wireless device.
 8. A method implemented in a BaseStation Subsystem (BSS) configured to interact with a Serving GPRSSupport Node (SGSN) and a target wireless device, the method comprising:receiving, from the SGSN, a BSS General Packet Radio Service (GPRS)Protocol (BSSGP) Down Link (DL)-UNITDATA Packet Data Unit (PDU) whichincludes a Logical Link Control (LLC) PDU intended for the targetwireless device, wherein the LLC PDU includes a Radio Resource LocationServices Protocol (RRLP) PDU, wherein the RRLP PDU further includes aRRLP Multilateration Timing Advance (MTA) Request message; transmitting,to the target wireless device, the LLC PDU which includes the RRLP PDU,wherein the RRLP PDU further includes the RRLP MTA Request Message;receiving a Packet Associated Control Channel (PACCH) acknowledgmentfrom the target wireless device; and, acquiring timing advanceinformation associated with the PACCH acknowledgment, wherein the BSS isinformed of a need to acquire the timing advance information by a flagwithin the BSSGP DL-UNITDATA PDU.
 9. The method of claim 8, wherein theflag is a code point in an information element.
 10. The method of claim8, further comprising transmitting, to a Serving Mobile Location Center(SMLC), a BSSMAP Connection Oriented Message which includes (i) theacquired timing advance information; and (ii) accuracy informationassociated with the target wireless device.